diff --git a/relik/reader/data/relik_reader_re_data.py b/relik/reader/data/relik_reader_re_data.py
index 84a8d58..b2a8fff 100644
--- a/relik/reader/data/relik_reader_re_data.py
+++ b/relik/reader/data/relik_reader_re_data.py
@@ -730,7 +730,7 @@ def flip_cands(flip_candidates, candidates):
 
                     candidates_encoding_result = (
                         candidates_encoding_result[:i]
-                        + candidates_encoding_result[len(sample.span_candidates) : i]
+                        + candidates_encoding_result[len(sample.span_candidates) : len(sample.span_candidates) + i]
                     )
                     if len(self.special_symbols_types) > 0:
                         candidates_entities_symbols = candidates_entities_symbols[:i]